Method for detecting and identifying installation error of main shaft and coaxiality of main shaft and C shaft

Abstract

The invention discloses a method for detecting and identifying an installation error of a main shaft and the coaxiality of the main shaft and a C shaft, and relates to the technical field of numerical control machine tool parameter measurement. The method comprises the following steps of: 1, collecting measurement data, and measuring and recording the position deviation of the ball center of a ball head detection rod by using a detection instrument when the C shaft and the main shaft are at different corner positions; 2, extracting measurement data when the C shaft rotates for at least one circle in the step 1, obtaining a sphere center movement radius by using a least square fitting circle, and calculating a main shaft installation inclination error by combining with different rod lengths of a ball head detection rod; 3, extracting measurement data when the C shaft and the main shaft rotate for at least one circle in the step 1, and performing sine function fitting to obtain a main shaft installation translation error and a main shaft and C shaft coaxiality error; 4, repeating the step 1 to the step 3, conducting multiple times of measurement, and obtaining the average value of the identification results. Separation and identification of the measurement position deviation value can be effectively achieved, and a data source is provided for rapid evaluation of the machine tool precision.

Description

technical field [0001] The invention relates to the technical field of numerically controlled machine tool parameter measurement, in particular to a method for detecting and identifying the installation error of a spindle and the coaxiality of the spindle and a C-axis. Background technique [0002] With the increasingly complex shapes and curved surfaces of CNC machining objects, CNC machine tools with large swing angles and large stroke ranges have been widely used. The biggest feature of this type of machine tool is that it has a C rotary axis, which expands the rotation range of the swing angle and the range of processed parts is also wider. The oscillating head composed of the spindle and the C-axis is an important functional part of the machine tool, and its rotation accuracy is a key indicator reflecting the performance of the CNC machine tool. Due to the rotation accuracy of the oscillating head, it is not only affected by its own geometric error, but also by the inst...

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Problems solved by technology

[0003] At present, for the spindle installation error and coaxiality detection of the CNC machine tool with the C rotary axis, there are traditional manual measurement methods such as the use of inspection rods, dial indicators and other instruments. The disadvantages are that it is easy to introduce human error and the degree of automation is low. The accuracy of the results depends on the skill level of the operator

In order to improve the level of automatic measurement, in the invention patent with the application number "CN201810601644.4", a circular grating and an autocollimator are used to complete the measurement and identification of the spindle rotation error. This method has high measurement accuracy, but it still does not consider the machine tool. The rotation error caused by the rotation of the C-axis will reduce the overall accuracy of the machine tool's swing head; when measuring the coaxiality of the spindle and the C-axis in the invention patent with the application number "CN201510779253.8", the installation of the spindle is not considered The influence of errors on the measurement results, the accuracy of the identification results depends on the precision of the spindle installation, but the actual situation is not optimistic

[0004] Generally speaking, in the prior art methods, the errors caused by the coaxiality of the C-axis and the installation of the spindle are not effectively integrated as the research object, so that the established detection and identification model is relatively simple, which is not conducive to effectively separating the comprehensive error of the rotary motion of the machine tool , it is also not conducive to clarify the mechanism of each error factor

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